Unlike POP mail, IMAP synchronises your mail across different devices. So if you check your mail on your cell phone, reply to a message and delete some spam, you won’t have to do it all again on your PC when you get home. Ideal for keeping things tidy when using different devices.
Log in to GMail, go to the settings page, click the ‘Forwarding and POP/IMAP’ tab and enable IMAP.
Now open your mail program of choice, I recommend Thunderbird for Windows and Apple Mail for Mac. Create a new account and choose IMAP (obviously) from the options menu. Everything is much the same as setting up a POP mail account, only now when you create, say, an ‘urgent’ label for certain pending e-mails, or a ‘to do’ list, any changes you make locally appear on all the devices you access that account from instantly.
Dead good that!